Jennifer Lopez and Alex Rodriguez’s romance is so serious, the couple has started looking for apartments together in Manhattan, Page Six has exclusively learned.

The A-list duo known as J-Rod looked at sprawling, multimillion-dollar apartments together on Park Avenue last week, according to a source.

Lopez, 48, already has a stunning penthouse apartment in NoMad overlooking Madison Square Park in NYC, which she bought in 2014 for $22 million.

The source said, “Jennifer and Alex are looking at apartments together that would be large enough for the both of them and their children. Jennifer already has a beautiful place in NoMad, but Alex is currently based in Miami and doesn’t have an apartment in the city.

“Jennifer will be in Manhattan a lot filming her NBC show ‘Shades of Blue,’ and Alex wants to be here with her. They are totally inseparable.”

While the pair has been romantically linked since March, J.Lo gushed about her relationship with the former Yankees slugger in a new interview with Hola. The star, who has a new Spanish album out titled “Por Primera Vez” (“For the First Time”), said, “I’m in a good relationship. I feel like I can say that for the first time — I don’t know — maybe ever,” she said, adding, “And not that I didn’t have great relationships, full of love and adventure, but this is the first relationship I’ve been where I feel like we really make each other better. We complement each other, and there’s really pure, true love. Just wanting to support the other person and make them happy. So there’s a different selflessness in the love that’s beautiful and different. And healthy!”

She has 9-year-old twins Max and Emme with ex-husband Marc Anthony, who fully approves of A-Rod, we’re told.

Meanwhile, Rodriguez, 42, has been focusing on building his real estate portfolio of commercial and residential properties in the US. He told The Street last week that he’s looking to pounce on more deals in the next 18 months in locations nationwide, including New York.